Jon Elson wrote:


The PTC thermistors are from Keystone Carbon Corp., I used these some years
ago. Not sure they are in business anymore, but the line may have been
picked up by one of the components manufacturers.

I did find this :
https://www.galco.com/buy/Keystone-C...Company/KC010L


** That pic looks exactly like a regular NTC thermistor.

Mains voltage rated PTCs are used in the AC supply to PSUs, both transformer and switchmode to provide anti-surge PLUS overload protection.

Impressive to see one doing its job, running stinking hot while allowing only 25mA or so into the faulty PSU.


..... Phil